1. Field of the Invention
This invention relates to a continuous process for the production of a CO-rich gas stream by the partial oxidation of a carbonaceous fuel. More specifically, the present invention relates to the production of synthesis gas by noncatalytic partial oxidation starting with liquid CO.sub.2, solid carbonaceous fuel e.g. ground coal, and a free-oxygen containing gas e.g. air, or substantially pure oxygen.
2. Description of the Prior Art
Oil embargoes coupled with already developing petroleum shortages have led to an energy crisis in this country. To help meet the accelerating demand for energy, exploration and development of conventional petroleum resources have been stepped up. However, long-term solutions demand that alternate energy resources be developed and utilized to the maximum degree. Coal is the most promising raw material in the USA for the production of synthetic natural gas (SNG) and synthesis gas i.e. mixtures of CO+H.sub.2. In the U.S. in 1970 the estimated recoverable coal reserves assuming 50 percent recovery were about 778 billion short tons. In comparison in the U.S. in 1974 the proved reserves of crude oil amounted to about 35 billion barrels.
H.sub.2 O is commonly used as a temperature moderator in the partial oxidation of hydrocarbonaceous fuels to produce synthesis gas. However, problems with water as a temperature moderator are encountered with solid carbonaceous fuels when water soluble solids separate and precipitate on heating surfaces in the system. Further, the high heat of vaporization of water reduces thermal efficiency. In coassigned U.S. Pat. No. 3,705,108 inert gases including CO.sub.2 were suggested to control the heat liberated by combustion of oil.
Nothing in the prior art teaches or suggests the subject invention wherein liquid carbon dioxide is mixed with a solid carbonaceous fuel e.g. ground coal to produce a pumpable slurry which is fed to an unpacked free-flow noncatalytic gas generator, where reaction takes place by partial oxidation to produce a CO-rich synthesis gas or fuel gas.